Fujitsu PRIMEQUEST 440, System Design Manual

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C122-B001-02EN 6-7
6.3 System Mirror
6.3 System Mirror
The PRIMEQUEST System Mirror duplicates main server components, such as,
memory, an address crossbar (XAI), a data crossbar (XDI), or a chip set, and reads
data from and writes data to both components at the same time. Since hardware
components and read/write are duplicated, even if a hardware component fails,
operation can be continued without stopping the system.
Table 6.1 contains the specifications of System Mirror.
Table 6.1 System Mirror Specifications
*1: Rate for the amount of installed memory
Figure 6.4 outlines the system configuration of System Mirror.
System Mirror duplicates important hardware in the system, i.e., the Xbar address
interconnect board (XAI) on which an address cross bar is mounted, and Xbar data
interconnect board (XDI) on which a data cross bar is mounted, memory, and the
inside of the chip set. Data is also simultaneously processed by using both of
duplicated components. Thus, even if one of two duplicated components fails, the
other component can continue operation without stopping the system.
Mode
Item
System Mirror
Address cross bar Duplicated
Data cross bar Duplicated
Memory Duplicated
Inside of a chip set Duplicated
Effective memory capacity 50% (*1)